REAL-TONE

The Real-Tone brand was a licenscee of RCA. It says so on the tube box. I'm not sure what that meant, since RCA was certainly active making tubes at that time and they were not licensing their name as companies did in later years. Perhaps Real-Tone made or bought tubes that met RCA
specs and paid to have 'RCA Licensed' on the box. This is a sealed, push through to test box.